Field of the Invention
This invention relates generally to electrical grounding systems for vehicles involved in the transportation of fluids and, more specifically, to a system, apparatus, and method for verifying a groundwire connection on a vehicle.
Description of Related Art
Discharge of static electricity can potentially create highly dangerous conditions in industries dealing with flammable substances. Particularly, static electricity can build up due to the flowing movement of finely powdered substances or low conductivity fluids in pipes or through mechanical agitation. Additionally, static charge may build up on a vehicle simply due to friction between the vehicle and any occupants or items contained therein. Flammable vapor clouds and clouds of finely powdered flammable substances can become combustible, and explosions have occurred due to static discharge in such dust or vapor clouds.
Significant contact-induced charge separation, or flow electrification, occurs when low conductivity fluids flow through pipelines or are mechanically agitated. Particularly, non-polar liquids, such as kerosene, gasoline, diesel, and light crude oils, as examples, often exhibit high levels of charge accumulation. However, charge accumulation may occur during the transfer of other fluids as well, including water and hydraulic fracturing fluids. The amount of charge accumulation increases at higher fluid velocities and larger pipe diameters, and accordingly, static charge generation in these systems is often controlled by limiting fluid velocity. Further, in many systems, an anti-static additive must be added to the fluid.
One way to reduce the risk of charge build-up is to electrically ground vehicles, particularly those engaged in fluid transfer, by providing a low-resistance pathway for electricity to travel between the machinery and the ground. However, such systems depend on the vehicle operator manually connecting a groundwire, and the need for doing so may not be readily apparent to vehicle operators.
Particularly in hydraulic fracturing operations, each well may be located at a remote location and such operations may require hundreds of trucks engaged in the transportation of water and/or hydraulic fracturing fluids to and from the well site. Accordingly, in such operations, it is particularly difficult to maintain accountability of the vehicle operators and ensure they follow the proper safety precautions, including grounding the vehicle prior to fluid transfer.